[en] The application of austenitic material especially susceptible to local corrosion and corrosion cracking, in both circuits of WWER nuclear power plants necessitated the investigation of the effects of possible electrolyte changes on the individual parameters of local corrosion. The methods are described of assessing the properties of oxide layers and deposits, such as the determination of the weight of an area unit of the oxide layer, the determination of porosity of layers and deposits, their mechanical strength, thickness and properties characterizing heat transfer in the layers. Attention is also paid to the physical and chemical properties of oxide layers and deposits, to their crystal structure, and to the determination of their chemical properties. It is shown that only a set of methods offering a complex picture of the whole problem area should be used in determining all properties. Results thus obtained can be used in the study of corrosion processes in the water-steam environment in nuclear power plants. (Z.M.)